JP6773001B2 - Refining conditions determination method, refining equipment control method, and molten iron refining method - Google Patents

Refining conditions determination method, refining equipment control method, and molten iron refining method Download PDF

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JP6773001B2
JP6773001B2 JP2017207434A JP2017207434A JP6773001B2 JP 6773001 B2 JP6773001 B2 JP 6773001B2 JP 2017207434 A JP2017207434 A JP 2017207434A JP 2017207434 A JP2017207434 A JP 2017207434A JP 6773001 B2 JP6773001 B2 JP 6773001B2
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安藤 誠
誠 安藤
岡田 淳
淳 岡田
新司 小関
新司 小関
新吾 佐藤
新吾 佐藤
操 浪川
操 浪川
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Description

本発明は、精錬処理条件の決定方法、精錬設備の制御方法及び溶鉄の精錬処理方法に関する。 The present invention relates to a method for determining refining treatment conditions, a method for controlling refining equipment, and a method for refining molten iron.

精錬設備である転炉では、精錬処理完了となる吹き止め時の溶鋼の成分濃度及び温度を目標値に合わせるため、スタティック制御と、サブランス測定に基づいたダイナミック制御とを組み合わせた制御が行われている(例えば、特許文献1参照)。
このうち、スタティック制御は、精錬処理の開始時から処理末期のサブランスによる溶鋼の成分濃度及び温度の測定(「サブランス測定」ともいう。)が行われるまでに用いられる制御である。スタティック制御では、精錬処理開始前に、物質収支及び熱収支に基づいた数式モデル等を用いて、吹き止め時の溶鋼の成分濃度及び温度を目標値に合わせるために必要な吹込酸素量及び各種副原料の投入量が決定される。そして、決定された処理条件に従って、脱炭処理が施されていない溶銑の処理が開始される。スタティック制御で用いられる数式モデルは、装入される溶銑の組成や温度、炉体耐火物の損耗度、排ガスの2次燃焼比率などを含み、物質収支や熱収支、熱力学計算、反応速度計算にもとづいて組み立てられている。
In the converter, which is a refining facility, control that combines static control and dynamic control based on sublance measurement is performed in order to match the component concentration and temperature of the molten steel at the time of blowing down when the refining process is completed to the target value. (See, for example, Patent Document 1).
Of these, the static control is a control used from the start of the refining process to the measurement of the component concentration and temperature of the molten steel by the sublance at the end of the process (also referred to as “sublance measurement”). In static control, before the start of the refining process, the amount of oxygen blown and various subs required to match the component concentration and temperature of the molten steel at the time of blow-off to the target value using a mathematical model based on the mass balance and heat balance. The amount of raw material input is determined. Then, according to the determined treatment conditions, the treatment of the hot metal that has not been decarburized is started. The mathematical model used in static control includes the composition and temperature of the hot metal to be charged, the degree of wear of the refractory of the furnace body, the secondary combustion ratio of the exhaust gas, etc., and includes the mass balance, heat balance, thermodynamic calculation, and reaction rate calculation. It is assembled based on.

一方、ダイナミック制御は、精錬処理の末期である、サブランス測定後から吹き止めまでの間に用いられる制御である。ダイナミック制御では、サブランス測定による溶鋼の成分濃度及び温度の測定結果に基づいて、スタティック制御で決定した吹込酸素量及び各種副原料の投入量を適正化する。これにより、吹き止め時の溶鋼の成分濃度及び温度の的中精度を向上させることができる。また、当然ながら、スタティック制御の制御精度が高ければ、ダイナミック制御の制御精度も向上する。
スタティック制御あるいはダイナミック制御で使用されている数式モデルは、過去の操業実績から導かれた物質収支及び熱収支によって構成されている。また、大量の操業データからその特徴量を抽出し利用しているものもある(特許文献2参照)。
On the other hand, the dynamic control is a control used from the sublance measurement to the blow-off, which is the final stage of the refining process. In the dynamic control, the amount of oxygen blown and the amount of input of various auxiliary materials determined by the static control are optimized based on the measurement results of the component concentration and the temperature of the molten steel by the sublance measurement. As a result, it is possible to improve the accuracy of hitting the component concentration and temperature of the molten steel at the time of blowing. Further, as a matter of course, if the control accuracy of static control is high, the control accuracy of dynamic control is also improved.
The mathematical model used in static control or dynamic control is composed of mass balance and heat balance derived from past operation results. In addition, there are some that extract the feature amount from a large amount of operation data and use it (see Patent Document 2).

特開2015−101785号公報JP 2015-101785 特許第4998661号公報Japanese Patent No. 4998661

上述のように、高温の溶鉄を精錬処理する転炉等の精錬設備では、精錬処理中の溶鉄の温度や成分濃度、界面形状等の精錬設備内部の状態をリアルタイムで把握することは困難である。このため、従来は、スタティック制御あるいはダイナミック制御を用いて、精錬処理をする方法が取られてきた。しかしながら、このような方法では、精錬処理を行う前から溶鉄の状態に応じた適切な精錬処理条件を予測することはできておらず、必ずしも効率的な精錬処理ができているとは言えなかった。また、従来の方法は、過去の精錬処理条件とそれに基づく実績データを使用するため、実際に過去に行われた実績そのもの、またはそこからの内挿または外挿でしか、精錬処理条件を決めることができなかった。 As described above, in a refining facility such as a converter that refines high-temperature molten iron, it is difficult to grasp the internal state of the refining facility such as the temperature, component concentration, and interface shape of the molten iron during the refining process in real time. .. For this reason, conventionally, a method of refining processing using static control or dynamic control has been adopted. However, with such a method, it is not possible to predict appropriate refining treatment conditions according to the state of molten iron even before the refining treatment is performed, and it cannot be said that efficient refining treatment is always possible. .. In addition, since the conventional method uses the past refining processing conditions and the actual data based on them, the refining processing conditions are determined only by the actual actual results performed in the past or the interpolation or extrapolation from the past. I couldn't.

そこで、本発明は、上記の課題に着目してなされたものであり、精錬処理を効率よく行うことができ、また過去には例がない精錬処理条件をも求めることができる、精錬処理条件の決定方法、精錬設備の制御方法及び溶鉄の精錬処理方法を提供することを目的としている。 Therefore, the present invention has been made by paying attention to the above-mentioned problems, and is a refining treatment condition that can efficiently perform a refining treatment and can also obtain a refining treatment condition that has never been seen in the past. It is an object of the present invention to provide a determination method, a method for controlling a refining facility, and a method for refining molten iron.

[1]溶鉄に精錬ガスを噴射して精錬処理を行う時の精錬処理条件を決定する方法であって、あらかじめ設定された精錬処理の初期条件及び終了条件をもとに精錬設備の内部の経時的な現象を数値解析で推定する解析工程と、前記数値解析の結果に基づいて、前記溶鉄の精錬処理条件を決定する決定工程と、を備えることを特徴とする精錬処理条件の決定方法。 [1] A method of determining refining processing conditions when refining gas is injected into molten iron to perform refining processing, and the aging of the inside of the refining equipment based on preset initial conditions and ending conditions of refining processing. A method for determining refining treatment conditions, which comprises an analysis step of estimating a specific phenomenon by numerical analysis and a determination step of determining the refining treatment conditions of the molten iron based on the result of the numerical analysis.

[2]前記解析工程では、複数の操業条件に基づいて設定される複数の計算条件で前記数値解析を行い、前記決定工程では、複数の前記計算条件のうち、前記数値解析により得られる計算結果が前記終了条件に適合する前記計算条件を選択し、適合した前記計算条件に該当する前記操業条件を、前記精錬処理条件として決定することを特徴とする上記[1]に記載の精錬処理条件の決定方法。
[3]前記解析工程では、少なくとも、前記溶鉄の自由界面の経時的な変化、スラグの自由界面の経時的な変化、前記溶鉄と前記精錬ガスとの化学反応、前記溶鉄内の化学反応、及び前記溶鉄と前記スラグとの化学反応、を推定することを特徴とする上記[1]または[2]に記載の精錬処理条件の決定方法。
[2] In the analysis step, the numerical analysis is performed under a plurality of calculation conditions set based on a plurality of operating conditions, and in the determination step, a calculation result obtained by the numerical analysis among the plurality of calculation conditions is performed. The refining treatment condition according to the above [1], wherein the calculation condition conforming to the termination condition is selected, and the operating condition corresponding to the conforming calculation condition is determined as the refining treatment condition. How to decide.
[3] In the analysis step, at least the change over time in the free interface of the molten iron, the change over time in the free interface of the slag, the chemical reaction between the molten iron and the refining gas, the chemical reaction in the molten iron, and The method for determining refining treatment conditions according to the above [1] or [2], wherein the chemical reaction between the molten iron and the slag is estimated.

[4]上記[1]〜[3]のいずれか1つに記載の精錬処理条件の決定方法により前記精錬処理条件を決定した後、前記精錬設備を制御し、前記精錬処理条件に従って前記溶鉄を精錬処理することを特徴とする精錬設備の制御方法。
[5]溶鉄に精錬ガスを噴射して精錬処理を行う精錬設備で前記溶鉄を精錬処理する際に、上記[1]〜[3]のいずれか1つに記載の精錬処理条件の決定方法により決定された精錬処理条件に従って、前記溶鉄を精錬処理することを特徴とする溶鉄の精錬処理方法。
[4] After determining the refining treatment conditions by the method for determining the refining treatment conditions according to any one of the above [1] to [3], the refining equipment is controlled to produce the molten iron according to the refining treatment conditions. A method of controlling refining equipment, which is characterized by refining.
[5] When refining the molten iron in a refining facility that injects refining gas into the molten iron to perform the refining treatment, the refining treatment condition is determined according to any one of the above [1] to [3]. A method for refining molten iron, which comprises refining the molten iron according to the determined refining treatment conditions.

本発明によれば、精錬処理を効率よく行うことができ、また過去には例がない精錬処理条件をも求めることができる、精錬処理条件の決定方法、精錬設備の制御方法及び溶鉄の精錬処理方法が提供される。 According to the present invention, the refining process can be efficiently performed, and the refining process conditions unprecedented in the past can be obtained. The refining process condition determination method, the refining facility control method, and the refining process of molten iron can be obtained. A method is provided.

本発明の一実施形態における転炉1を示す模式図である。It is a schematic diagram which shows the converter 1 in one Embodiment of this invention. 本発明の一実施形態に係る溶鉄の精錬処理方法を示すフローチャートである。It is a flowchart which shows the refining processing method of molten iron which concerns on one Embodiment of this invention.

以下の詳細な説明では、本発明の完全な理解を提供するように、本発明の実施形態を例示して多くの特定の細部について説明する。しかしながら、かかる特定の細部の説明がなくても1つ以上の実施態様が実施できることは明らかであろう。また、図面は、簡潔にするために、周知の構造及び装置が略図で示されている。 The following detailed description illustrates many specific details by exemplifying embodiments of the invention to provide a complete understanding of the invention. However, it will be clear that one or more embodiments can be implemented without such particular detail description. Also, for the sake of brevity, the drawings are schematic representations of well-known structures and devices.

<溶鉄の精錬処理方法>
本発明の一実施形態に係る溶鉄の精錬処理方法について説明する。本実施形態では、図1に示す精錬設備である転炉1にて、溶銑である溶鉄2を精錬処理として脱炭処理し、炭素濃度の低い溶鋼を溶製する。
転炉1は、内壁に耐火物が設けられた精錬容器である炉体11と、炉体11の開口部に上方から挿入可能に構成される上吹きランス12と、炉体11の底部に設けられた複数の底吹きノズル13とを有する精錬装置である。転炉1による脱炭処理では、炉体11の内部に収容された溶鉄2に、底吹きノズル13から撹拌用の不活性ガスである撹拌ガス5が吹き込まれ、さらに、上吹きランス12から酸素を含む精錬ガス3が吹き込まれることで、溶鉄2が処理される。なお、溶鉄2の浴面には、精錬ガスによる酸化反応及び添加される副原料等により、溶鉄2よりも比重の小さい液相であるスラグ4が形成される。
<Refining method of molten iron>
A refining treatment method for molten iron according to an embodiment of the present invention will be described. In the present embodiment, in the converter 1 which is the refining facility shown in FIG. 1, molten iron 2 which is hot metal is decarburized as a refining treatment to melt molten steel having a low carbon concentration.
The converter 1 is provided at the bottom of the furnace body 11, a furnace body 11 which is a refractory vessel provided with a refractory on the inner wall, a top blowing lance 12 which is configured to be inserted into the opening of the furnace body 11 from above. It is a refractory apparatus having a plurality of bottom blowing nozzles 13. In the decarburization treatment by the converter 1, a stirring gas 5, which is an inert gas for stirring, is blown into the molten iron 2 housed inside the furnace body 11 from the bottom blowing nozzle 13, and oxygen is further blown from the top blowing lance 12. The molten iron 2 is processed by blowing the refining gas 3 containing the above. On the bath surface of the molten iron 2, a slag 4 which is a liquid phase having a specific gravity smaller than that of the molten iron 2 is formed by an oxidation reaction by a refining gas and an auxiliary raw material added.

本実施形態では、図2に示すように、まず、炉体11の内部の精錬処理時の現象を模擬した数値解析をする解析工程を行う(S100)。ステップS100では、予め構築された、転炉1の形状を模擬した数値解析モデルを作成して、炉体11内部の状態を経時的に推定する数値解析を行う。
本実施形態の数値解析では、精錬処理の初期条件を出発点として、所定の計算条件によって溶鉄2の経時変化を求める。精錬処理の初期条件とは、溶鉄2が転炉1に装入された直後の、溶鉄2の状態を示すものであり、例として溶鉄2の成分組成、温度、装入量、溶鉄2の界面の位置等があげられる。
In the present embodiment, as shown in FIG. 2, first, an analysis step of performing a numerical analysis simulating a phenomenon during a refining process inside the furnace body 11 is performed (S100). In step S100, a numerical analysis model that simulates the shape of the converter 1 constructed in advance is created, and numerical analysis is performed to estimate the state inside the furnace body 11 over time.
In the numerical analysis of the present embodiment, the change with time of the molten iron 2 is obtained by a predetermined calculation condition with the initial condition of the refining process as a starting point. The initial conditions of the refining treatment indicate the state of the molten iron 2 immediately after the molten iron 2 is charged into the converter 1, and as an example, the component composition, temperature, charge amount, and interface of the molten iron 2 of the molten iron 2. The position of is given.

溶鉄2の成分組成や温度は、転炉1に装入される前に判明している。また、転炉1内での溶鉄2の界面の位置が初期条件の一つになるが、転炉1の大きさや形状は事前に判明しており、装入量が決まれば界面の位置も自動的に求まる。
初期条件が決まった後に、実際に数値解析を行う。
数値解析では、底吹きノズル13から撹拌ガス5を吹き込み、上吹きランス12から所定の流量、速度で精錬ガス3を溶鉄2に吹き付ける条件で実施する。さらに、炉体11内部での各種ガスや溶鉄2、スラグ4等の流体の流れを、各種化学反応と連成させて解くことで、炉体11内部の状態を経時的に推定する。各種ガスとは、精錬ガス3及び撹拌ガス5に加え、脱炭反応や燃焼反応によって発生するCOなどの気体成分である。炉体11内部の状態とは、上述のものに加え、精錬ガス3を吹き付けたことによる溶鉄2の表面の形状の変化、スプラッシュの発生の有無等があげられる。
The composition and temperature of the molten iron 2 are known before being charged into the converter 1. Further, the position of the interface of the molten iron 2 in the converter 1 is one of the initial conditions, but the size and shape of the converter 1 are known in advance, and the position of the interface is automatically determined once the charging amount is determined. Can be found.
After the initial conditions are decided, the numerical analysis is actually performed.
The numerical analysis is carried out under the condition that the stirring gas 5 is blown from the bottom blowing nozzle 13 and the refining gas 3 is blown onto the molten iron 2 from the top blowing lance 12 at a predetermined flow rate and speed. Further, the state inside the furnace body 11 is estimated over time by solving the flow of various gases and fluids such as molten iron 2 and slag 4 inside the furnace body 11 by coupling them with various chemical reactions. The various gases are gas components such as CO generated by a decarburization reaction or a combustion reaction in addition to the refining gas 3 and the stirring gas 5. The state inside the furnace body 11 includes, in addition to the above-mentioned ones, a change in the surface shape of the molten iron 2 due to the spraying of the refining gas 3, the presence or absence of splash generation, and the like.

数値解析は、溶鉄2が所定の精錬処理の終了条件になるまで行われる。ここで、精錬処理の終了条件の具体例として、溶鉄2の所定の成分組成及び温度があげられる。
数値解析結果が精錬処理終了条件と完全に一致しない場合もあるが、このような場合は、精錬処理の終了条件に許容範囲を設け、この許容範囲内に計算結果が入ればよい、として、数値解析を終了することもできる。
ただし、計算が収束せずに解が得られない場合もあるので、計算時間には上限を設けることが望ましい。実際の精錬では、ある精錬の操業が終了し、次の精錬のために溶鉄2が所定の位置に運ばれてくるまでの時間は、それほど長くはない。その間に数値解析を完了させて操業条件を決め、精錬の準備を行わなければなければならないから、計算時間の上限は30分程度以下であることが好ましく、10分以下であることがさらに好ましい。
Numerical analysis is performed until the molten iron 2 reaches a predetermined refining process end condition. Here, as a specific example of the end condition of the refining treatment, a predetermined component composition and temperature of the molten iron 2 can be mentioned.
In some cases, the numerical analysis result does not completely match the refining process end condition. In such a case, a permissible range should be set in the refining process end condition, and the calculation result should be within this permissible range. You can also end the analysis.
However, it is desirable to set an upper limit on the calculation time because the calculation may not converge and a solution may not be obtained. In actual refining, the time until the operation of one refining is completed and the molten iron 2 is brought into a predetermined position for the next refining is not so long. During that time, the numerical analysis must be completed, the operating conditions must be determined, and the refining preparation must be performed. Therefore, the upper limit of the calculation time is preferably about 30 minutes or less, and more preferably 10 minutes or less.

流体の流れを解く数値解析手法としては、自由界面の経時的な変化を予測可能で、化学反応を考慮することができる方法であればよい。自由界面は、気相と液相であるスラグ4との界面、気相と液相である溶鉄2との界面、スラグ4と溶鉄2との界面等の異相界面である。このような数値解析手法としては、例えば、有限体積法にVoF(Volume of Fluid)法を組み合わせた手法等の格子法を用いてもよく、SPH(Smoothed Particle Hydrodynamics)やMPS(Moving Particle Semi-implicit)等の粒子法を用いてもよい。なお、数値解析モデルには、用いられる数値解析手法に応じた物理モデルが適用される。
考慮する化学反応としては、精錬ガス3による溶鉄2中の鉄や炭素等の異相界面での酸化反応、溶鉄2中の酸素(FeO)による炭素等の酸化反応、下記(1)式で示す精錬ガス3と発生した一酸化炭素(CO)ガスとの反応である2次燃焼反応等を考慮する。
2CO+O→CO ・・・(1)
As a numerical analysis method for solving the flow of a fluid, any method that can predict the change of the free interface with time and can consider the chemical reaction may be used. The free interface is a heterogeneous interface such as an interface between a gas phase and a slag 4 which is a liquid phase, an interface between a gas phase and a molten iron 2 which is a liquid phase, and an interface between a slag 4 and a molten iron 2. As such a numerical analysis method, for example, a lattice method such as a method in which a finite volume method and a VoF (Volume of Fluid) method are combined may be used, and SPH (Smoothed Particle Hydrodynamics) or MPS (Moving Particle Semi-implicit) may be used. ) Etc. may be used. A physical model corresponding to the numerical analysis method used is applied to the numerical analysis model.
The chemical reactions to be considered include an oxidation reaction of iron and carbon in the molten iron 2 at the heterophase interface by the refining gas 3, an oxidation reaction of carbon and the like by oxygen (FeO) in the molten iron 2, and refining represented by the following equation (1). Consider the secondary combustion reaction, which is the reaction between the gas 3 and the generated carbon monoxide (CO) gas.
2CO + O 2 → CO 2 ... (1)

これにより、炉体11内の状態として、各相の各箇所における溶鉄2の成分変化や、スラグの発生状況、反応によるガスの発生状況、温度変化等を予測することができる。ここで、各箇所とは、格子法を用いる場合には離散処理により分割された各メッシュであり、粒子法では計算に用いる粒子である。そして、自由界面での化学反応の反応量を予測する場合、自由界面の面積や形状が考慮される。転炉1における脱炭処理では、精錬ガスによる溶鉄2中の炭素の酸化反応は、精錬ガスのジェット流の衝突によって自由界面に形成された凹部付近で主に進行する。このため、例えば、自由界面の面積や形状の算出結果に基づいて脱炭反応の反応量である脱炭量を算出、または自由界面の経時的な変化(時間変動)と脱炭反応とを連成させて脱炭量を算出することにより、挙動をより正確に推定することができ、脱炭量をより正確に推定することができる。さらに、格子法を用いる場合には各メッシュでの気液体積分率、粒子法を用いる場合には各粒子の挙動を考慮することで、飛散した溶鉄2であるスプラッシュの発生挙動を推定することもできる。 As a result, it is possible to predict changes in the composition of molten iron 2 at each location in each phase, slag generation status, gas generation status due to reaction, temperature change, and the like as the state inside the furnace body 11. Here, each location is each mesh divided by discrete processing when the lattice method is used, and particles used for calculation in the particle method. Then, when predicting the reaction amount of the chemical reaction at the free interface, the area and shape of the free interface are taken into consideration. In the decarburization treatment in the converter 1, the oxidation reaction of carbon in the molten iron 2 by the refining gas proceeds mainly in the vicinity of the recess formed at the free interface by the collision of the jet flow of the refining gas. Therefore, for example, the decarburization amount, which is the reaction amount of the decarburization reaction, is calculated based on the calculation result of the area and shape of the free interface, or the change over time (time variation) of the free interface and the decarburization reaction are linked. By forming and calculating the decarburized amount, the behavior can be estimated more accurately, and the decarburized amount can be estimated more accurately. Furthermore, when the lattice method is used, the gas-liquid integration rate in each mesh is taken into consideration, and when the particle method is used, the behavior of each particle is taken into consideration to estimate the generation behavior of the splash of the scattered molten iron 2. it can.

また、上述のように、炉体11内部の状態の推定は、溶鉄2の成分濃度及び温度が所定の目標値となった終了状態となるまで、経時的な数値解析によって行われる。例えば、ステップS100では、初期条件から一定時間(例えば、10−5s)経過後の状態を数値解析により推定し、その後は処理終了の状態となるまで、直前に予測された状態を初期条件として一定時間経過後の状態の推定が数値解析により繰り返し行われることで、経時的な数値解析が行われる。
ステップS100では、数値解析により炉体11の内部の状態を推定することにより、上述の計算条件における精錬処理での処理結果が得られる。処理結果は、精錬処理において評価される慣用的な各種の指標を示すものであり、例えば、脱炭酸素効率や脱炭速度、処理時間、スプラッシュの発生量等の指標である。
Further, as described above, the state inside the furnace body 11 is estimated by numerical analysis over time until the component concentration and temperature of the molten iron 2 reach the final state where the predetermined target values are reached. For example, in step S100, the state after a lapse of a certain time (for example, 10-5 s) from the initial condition is estimated by numerical analysis, and then the state predicted immediately before is used as the initial condition until the processing is completed. Numerical analysis over time is performed by repeatedly estimating the state after a certain period of time by numerical analysis.
In step S100, by estimating the internal state of the furnace body 11 by numerical analysis, the processing result in the refining process under the above-mentioned calculation conditions can be obtained. The treatment result shows various conventional indexes evaluated in the refining treatment, for example, an index such as decarboxylation efficiency, decarburization rate, treatment time, and amount of splash generated.

数値計算で炉体11の内部の状態の推定するためには、所定の計算条件が必要になる。計算条件は、実際の精錬処理を行う時に必要になる操業条件から設定される。例えば、上吹きランス12の浴面からの高さであるランス高さや、上吹きランス12から噴射される精錬ガス3の流量及び速度、底吹きノズル13から吹き込まれる不活性ガスの流量及び速度等があげられる。操業条件と計算条件は、1対1で対応しており、操業条件が決まると、それに合わせた計算条件が設定される。実際の精錬では、操業条件は複数想定されるので、計算条件も想定される操業条件の数に合わせて、設定される。
実際の精錬では、操業条件が精錬の途中で変わることもあるので、計算条件もそれを反映しておくべきである。しかし、計算条件によっては、溶鉄2が所定の成分組成や温度にならなかったり、計算が収束せずに解が得られなかったりする場合もある。このような計算条件は、操業としては不適であると判断される。
In order to estimate the internal state of the furnace body 11 by numerical calculation, predetermined calculation conditions are required. The calculation conditions are set from the operating conditions required when performing the actual refining process. For example, the lance height, which is the height of the top-blown lance 12 from the bath surface, the flow rate and speed of the refining gas 3 injected from the top-blown lance 12, the flow rate and speed of the inert gas blown from the bottom-blown nozzle 13, and the like. Can be given. There is a one-to-one correspondence between the operating conditions and the calculation conditions, and once the operating conditions are determined, the calculation conditions are set accordingly. In actual refining, a plurality of operating conditions are assumed, so the calculation conditions are also set according to the number of assumed operating conditions.
In actual refining, operating conditions may change during refining, so the calculation conditions should also reflect that. However, depending on the calculation conditions, the molten iron 2 may not reach a predetermined component composition or temperature, or the calculation may not converge and a solution may not be obtained. Such calculation conditions are judged to be unsuitable for operation.

ステップS100の後、ステップS100での数値解析の結果に基づいて、溶鉄2の精錬処理条件を決定する決定工程を行う(S102)。前述したように、ステップS100では、複数の計算条件に基づいて数値解析が行われ、それぞれ計算結果が求まる。ステップS102では、これらの計算結果の中から、あらかじめ設定された精錬処理の終了条件を満たすものを選択する。
精錬処理の終了条件と一致する計算条件があれば、その計算条件を選択する。しかし、この計算条件が複数ある場合は、さらに選択条件を追加する。選択条件は、具体的には、脱炭酸素効率や脱炭速度、処理時間、スプラッシュの発生量等の複数の指標を例示することができる。これらの指標のうち、少なくとも一つの指標が、選択条件として目的に応じて任意に設定される。たとえば、予め設定される選択条件が、脱炭酸素効率が所定値以上であるとした場合、適合する複数の計算条件のうち、最も脱炭酸素効率が高い計算条件が選択される。これらの選択条件は、鋼種や精錬コスト等を考慮して、適宜設定することができる。
After step S100, a determination step of determining the refining treatment conditions for molten iron 2 is performed based on the result of the numerical analysis in step S100 (S102). As described above, in step S100, numerical analysis is performed based on a plurality of calculation conditions, and calculation results are obtained for each. In step S102, from these calculation results, one that satisfies the preset end condition of the refining process is selected.
If there is a calculation condition that matches the end condition of the refining process, select that calculation condition. However, if there are multiple calculation conditions, additional selection conditions are added. Specifically, the selection condition can exemplify a plurality of indexes such as decarboxylation efficiency, decarburization rate, treatment time, and amount of splash generated. At least one of these indicators is arbitrarily set as a selection condition according to the purpose. For example, when the preset selection condition is that the decarboxylation efficiency is equal to or higher than a predetermined value, the calculation condition having the highest decarboxylation efficiency is selected from among a plurality of matching calculation conditions. These selection conditions can be appropriately set in consideration of the steel type, refining cost, and the like.

次いで、選択した計算条件に対応する操業条件を決定する。この操業条件が、実際に精錬処理を行う時の精錬処理条件になる。
ステップS100,S102の処理は、計算機により行われる。この計算機は、精錬処理前及び精錬処理後の溶鉄2の条件(成分濃度や温度等)が入力されることで、上述の数値解析の計算及び精錬処理条件の決定を行う。
Then, the operating conditions corresponding to the selected calculation conditions are determined. This operating condition becomes the refining processing condition when the refining processing is actually performed.
The processing of steps S100 and S102 is performed by a computer. This computer calculates the above-mentioned numerical analysis and determines the refining treatment conditions by inputting the conditions (component concentration, temperature, etc.) of the molten iron 2 before and after the refining treatment.

ステップS102の後、ステップS102で決定された精錬処理条件に従って、転炉1にて実際に溶鉄2を精錬処理する精錬処理工程が行われる(S104)。ステップS104での精錬処理は、ステップS102で決定された精錬処理条件となるように転炉1を制御することで行われる。転炉1の制御は、精錬処理条件を決定する計算機自体が行ってもよく、この計算機に接続された制御装置が行ってもよい。また、ステップS104での精錬処理は、ステップS102で決定された精錬処理条件がモニタ等の表示機器に表示され、作業者が表示された精錬処理条件にしたがって、転炉1を制御することで行われてもよい。
つまり、本実施形態によれば、ステップS100の解析工程及びステップS102の決定工程により精錬処理条件が決定され、その後、決定された精錬処理条件に応じて、精錬設備である転炉1が制御されることで、溶鉄2が精錬処理される。
After step S102, a refining process step of actually refining the molten iron 2 in the converter 1 is performed according to the refining process conditions determined in step S102 (S104). The refining process in step S104 is performed by controlling the converter 1 so as to meet the refining process conditions determined in step S102. The control of the converter 1 may be performed by the computer itself that determines the refining processing conditions, or may be performed by a control device connected to the computer. Further, the refining process in step S104 is performed by displaying the refining process conditions determined in step S102 on a display device such as a monitor and controlling the converter 1 according to the displayed refining process conditions by the operator. You may be broken.
That is, according to the present embodiment, the refining processing conditions are determined by the analysis step of step S100 and the determination step of step S102, and then the converter 1 which is a refining facility is controlled according to the determined refining processing conditions. As a result, the molten iron 2 is refined.

従来は、過去の精錬処理条件とそれに基づく実績データを使用して操業条件を決定するため、実際に過去に行われた実績そのもの、あるいはそこからの内挿または外挿でしか、精錬処理条件を決めることができなかった。それに対して本実施形態によれば、溶鉄2の初期条件から出発して、種々の計算条件で数値解析によって溶鉄2の状態を経時的に求め、最適な操業条件を求めることが可能であり、これによって過去に実績が無い条件であっても、操業条件を求めることができる。 Conventionally, since the operating conditions are determined using the past refining processing conditions and the actual data based on them, the refining processing conditions are determined only by the actual actual results performed in the past or by interpolation or extrapolation from them. I couldn't decide. On the other hand, according to the present embodiment, it is possible to obtain the state of the molten iron 2 over time by numerical analysis under various calculation conditions, starting from the initial conditions of the molten iron 2, and to obtain the optimum operating conditions. As a result, operating conditions can be obtained even if there are no records in the past.

<変形例>
以上で、特定の実施形態を参照して本発明を説明したが、これら説明によって発明を限定することを意図するものではない。本発明の説明を参照することにより、当業者には、開示された実施形態とともに種々の変形例を含む本発明の別の実施形態も明らかである。従って、特許請求の範囲に記載された発明の実施形態には、本明細書に記載したこれらの変形例を単独または組み合わせて含む実施形態も網羅すると解すべきである。
<Modification example>
Although the present invention has been described above with reference to specific embodiments, it is not intended to limit the invention by these descriptions. By reference to the description of the invention, one of ordinary skill in the art will appreciate other embodiments of the invention that include various modifications as well as the disclosed embodiments. Therefore, it should be understood that the embodiments of the invention described in the claims also include embodiments including these modifications described in the present specification alone or in combination.

例えば、上記実施形態では、精錬設備が脱炭処理を行う転炉1であるとしたが、本発明はかかる例に限定されない。精錬設備は、酸素ガス等の気体を用いて、溶銑や溶鋼といった溶鉄2を精錬処理する設備であれば他のものであってもよい。例えば、精錬設備は、上吹きランスから溶鉄に酸素を含む精錬ガス等を吹き込むことで、溶鉄の脱珪や脱燐、脱硫といった脱炭処理前の予備処理を行う転炉型の予備処理炉であってもよい。また、精錬設備は、脱炭処理後の二次精錬工程にて用いられる、真空脱ガス装置であってもよい。真空脱ガス装置では、極低炭素鋼等を溶製する際に、真空槽内を環流する溶鉄に対して、真空槽内に設けられた上吹きランスから酸素ガスを吹き付けることで脱炭反応を促進させている。さらに、精錬設備は、上吹きランスから酸化性ガスを噴射する機能を備えた溶融還元炉であってもよい。 For example, in the above embodiment, the refining facility is a converter 1 that performs decarburization treatment, but the present invention is not limited to such an example. The refining facility may be any other facility as long as it is a facility for refining molten iron 2 such as hot metal or molten steel using a gas such as oxygen gas. For example, a refining facility is a converter-type pretreatment furnace that performs pretreatment before decarburization such as desiliconization, dephosphorization, and desulfurization of molten iron by blowing refining gas containing oxygen into molten iron from a top-blown lance. There may be. Further, the refining facility may be a vacuum degassing device used in the secondary refining step after the decarburization treatment. In the vacuum degassing device, when melting ultra-low carbon steel, etc., oxygen gas is blown from the top blowing lance provided in the vacuum tank to the molten iron circulating in the vacuum tank to carry out a decarburization reaction. It is promoting. Further, the refining facility may be a melt-reduction furnace having a function of injecting an oxidizing gas from a top-blown lance.

さらに、上記実施形態の解析工程では、単純化のため、精錬設備内で起きる化学反応として脱炭反応とそれに起因した燃焼反応を考慮するとしたが、本発明はかかる例に限定されない。精錬設備で生じる化学反応は様々であり、考慮したい条件に応じて考慮する化学反応を任意に設定することができる。例えば、脱炭反応及び二次燃焼反応に加えて、転炉1にて脱炭処理を行う場合において溶鉄2中、溶鉄2とスラグ4との異相界面または溶鉄2と気相との異相界面において生じる可能性のある、脱燐反応や脱珪反応等の他の反応を考慮してもよい。脱珪反応では、溶鉄2中の珪素が酸化されスラグ4の一部となることで、溶鉄2中の珪素濃度が低減する。また、脱燐反応では、溶鉄2中の燐が酸化されて燐酸化物となり、その後、燐酸化物がスラグ中のCaOと化合物を形成することで、溶鉄2中の燐濃度が低減する。なお、予測精度の観点からは、化学反応や物質の移動等の全ての要素を含んだ計算を行うことが好ましいが、計算する要素が複雑化するほど計算に時間が掛かることとなる。このため、あまり重要でないと事前にわかっている要素については、その要素を省略してもよい。 Further, in the analysis step of the above embodiment, for the sake of simplicity, the decarburization reaction and the combustion reaction caused by the decarburization reaction are considered as the chemical reaction occurring in the refining facility, but the present invention is not limited to such an example. There are various chemical reactions that occur in the refining equipment, and the chemical reactions to be considered can be arbitrarily set according to the conditions to be considered. For example, in the case of decarburizing in the converter 1 in addition to the decarburization reaction and the secondary combustion reaction, in the molten iron 2, at the different phase interface between the molten iron 2 and the slag 4 or the different phase interface between the molten iron 2 and the gas phase. Other reactions that may occur, such as dephosphorization and desiliconization, may be considered. In the desiliconization reaction, the silicon in the molten iron 2 is oxidized and becomes a part of the slag 4, so that the silicon concentration in the molten iron 2 is reduced. Further, in the dephosphorization reaction, phosphorus in the molten iron 2 is oxidized to become a phosphoric acid oxide, and then the phosphoric acid forms a compound with CaO in the slag, so that the phosphorus concentration in the molten iron 2 is reduced. From the viewpoint of prediction accuracy, it is preferable to perform a calculation including all elements such as a chemical reaction and mass transfer, but the more complicated the elements to be calculated, the longer the calculation will take. For this reason, elements that are known in advance to be less important may be omitted.

さらに、上記実施形態の解析工程及び決定工程では、一例として、精錬処理開始から精錬処理終了までの間における精錬処理条件として、各種の操業条件を一定とするとしたが、本発明はかかる例に限定されない。精錬処理の期間を複数に分け、各期間において解析工程及び決定工程を行うことで、期間によって精錬処理条件が異なるようにしてもよい。例えば、溶銑から溶鋼を溶製する脱炭処理の場合、通常、脱炭速度の違いから、溶銑予備処理の実施程度に応じて、精錬処理の期間を2つあるいは3つに分けることができる。これらの期間では、脱炭速度の律速となる機構が異なるため、脱炭速度を向上させるための最適な操業条件が異なる可能性がある。このため、炭素濃度に応じて、精錬処理の期間を複数に分け、各期間において解析工程及び決定工程を行うことで、操業条件を処理時間に応じて変化させた精錬処理条件を決定してもよい。 Further, in the analysis step and the determination step of the above-described embodiment, as an example, various operating conditions are set to be constant as the refining treatment conditions from the start of the refining treatment to the end of the refining treatment, but the present invention is limited to such examples. Not done. By dividing the refining process into a plurality of periods and performing the analysis step and the determination step in each period, the refining process conditions may be different depending on the period. For example, in the case of decarburization treatment in which molten steel is melted from hot metal, the refining treatment period can usually be divided into two or three depending on the degree of hot metal pretreatment due to the difference in decarburization rate. During these periods, the mechanism that determines the decarburization rate is different, so the optimum operating conditions for improving the decarburization rate may differ. Therefore, even if the refining treatment period is divided into a plurality of periods according to the carbon concentration and the analysis step and the determination step are performed in each period, the refining treatment conditions in which the operating conditions are changed according to the treatment time are determined. Good.

さらに、上記実施形態では、精錬処理を行う直前に、解析工程及び決定工程を行うことにより精錬処理条件を決定するとしたが、本発明はかかる例に限定されない。例えば、精錬処理前の溶鉄2の成分濃度及び温度、並びに精錬処理後の溶鉄2の目標成分濃度及び目標温度が、それぞれ所定の範囲内となることが分かっている場合には、これらの条件に応じて予め解析工程及び決定工程を行うことで精錬処理条件を決定してもよい。この場合、例えば、精錬処理前の溶鉄2の炭素濃度及び温度、並びに精錬処理後の溶鉄2の炭素濃度及び温度の条件をそれぞれ複数の範囲に分ける。次いで、各条件の全ての組み合わせにおいて目的に適合する精錬処理条件を、解析工程及び決定工程を行うことで決定する。そして、精錬処理を行う際には、これらの精錬処理条件をテーブルとして、精錬処理前後の溶鉄2の条件に合致する精錬処理条件をテーブルから抽出することで、最終的な精錬処理条件を決定してもよい。このようにすることで、数値解析に要する時間の長さに関係なく、適用することができるため、より複雑なモデルの適用が容易となる。 Further, in the above embodiment, the refining treatment conditions are determined by performing the analysis step and the determination step immediately before the refining treatment, but the present invention is not limited to such an example. For example, if it is known that the component concentration and temperature of the molten iron 2 before the refining treatment and the target component concentration and the target temperature of the molten iron 2 after the refining treatment are within the predetermined ranges, these conditions are met. The refining treatment conditions may be determined by performing the analysis step and the determination step in advance accordingly. In this case, for example, the conditions of the carbon concentration and temperature of the molten iron 2 before the refining treatment and the carbon concentration and temperature of the molten iron 2 after the refining treatment are each divided into a plurality of ranges. Next, the refining treatment conditions suitable for the purpose in all combinations of each condition are determined by performing an analysis step and a determination step. Then, when the refining process is performed, these refining process conditions are used as a table, and the refining process conditions that match the conditions of the molten iron 2 before and after the refining process are extracted from the table to determine the final refining process conditions. You may. By doing so, it can be applied regardless of the length of time required for numerical analysis, so that a more complicated model can be easily applied.

さらに、上記実施形態では、決定された精錬処理条件に従って精錬処理を最後まで行うとしたが、本発明はかかる例に限定されない。例えば、排ガス中のCO・CO濃度の測定や、サブランスによる炭素濃度の測定等の測定方法を用いて、精錬処理中に炉体11内部の温度や成分濃度等の状態を測定する工程をさらに有していてもよい。この場合、測定した結果と、数値解析による予測結果とから、測定時点における予測結果の実績とのずれを算出し、このずれを修正するように精錬処理条件を調整するようにしてもよい。例えば、脱炭速度の予測結果が測定結果よりも低く、溶鉄2の炭素濃度が高い場合には、ずれが判明した以降に行われる処理では、脱炭速度を測定結果に合わせたものとして、精錬ガスの流量増加や処理時間の延長といった調整を行ってもよい。 Further, in the above embodiment, the refining treatment is performed to the end according to the determined refining treatment conditions, but the present invention is not limited to such an example. For example, a step of measuring the state such as the temperature and component concentration inside the furnace body 11 during the refining process by using a measuring method such as measuring the CO / CO 2 concentration in the exhaust gas or measuring the carbon concentration by sublance is further performed. You may have. In this case, the deviation between the measured result and the predicted result by the numerical analysis may be calculated from the actual result of the predicted result at the time of measurement, and the refining processing conditions may be adjusted so as to correct this deviation. For example, if the predicted decarburization rate is lower than the measurement result and the carbon concentration of the molten iron 2 is high, in the treatment performed after the deviation is found, the decarburization rate is adjusted to the measurement result and refined. Adjustments such as increasing the gas flow rate and extending the processing time may be made.

さらに、上記実施形態では、転炉1が図1に示す構成であるとしたが、本発明はかかる例に限定されない。転炉1は、精錬ガスを噴射する上吹きランス12を有し、溶鉄2の脱炭処理等に用いられる慣用的なものであれば、他の構成であってもよい。例えば、底吹きノズル13からは、不活性ガスである撹拌ガス5の代わりに、撹拌に加えて酸化反応の促進を目的として、酸素を含む酸化性ガスを吹き込まれてもよい。また、上吹きランス12は、酸化性ガスに加え、酸化性ガスとは異なるノズルから粉状の石灰と搬送用のガス(不活性ガス等)を吹き込む構成であってもよい。 Further, in the above embodiment, the converter 1 has the configuration shown in FIG. 1, but the present invention is not limited to such an example. The converter 1 has a top-blown lance 12 for injecting refining gas, and may have another configuration as long as it is a conventional one used for decarburization of molten iron 2. For example, instead of the stirring gas 5 which is an inert gas, the bottom blowing nozzle 13 may blow an oxidizing gas containing oxygen for the purpose of promoting the oxidation reaction in addition to stirring. Further, the top-blown lance 12 may be configured to blow powdered lime and a transporting gas (inert gas or the like) from a nozzle different from the oxidizing gas in addition to the oxidizing gas.

さらに、上記実施形態では、予測に際し、精錬設備内部での気相及び液相を考慮するとしたが、本発明はかかる例に限定されない。例えば、気相及び液相に加えて、固相を考慮するようにしてもよい。転炉1での精錬処理では、成分調整や精錬反応の促進を目的に、合金鉄や媒溶材等の各種副原料が添加される。このような副原料は、炉体11内に添加され、溶融することで溶鉄2やスラグ4と反応する。また、溶鉄2の製造コストの低減や温室効果ガスの削減を目的に、溶鉄2と共に鉄源となるスクラップが炉体11内に添加されることがある。このため、副原料やスクラップを固相として計算モデルに組み込み、この固相の溶融や溶融後の化学反応等を考慮することで、実際の操業により即した計算を行うことができるようになる。 Further, in the above embodiment, the gas phase and the liquid phase inside the refining facility are taken into consideration in the prediction, but the present invention is not limited to such an example. For example, the solid phase may be considered in addition to the gas and liquid phases. In the refining treatment in the converter 1, various auxiliary raw materials such as ferroalloys and medial materials are added for the purpose of adjusting the components and promoting the refining reaction. Such an auxiliary material is added into the furnace body 11 and melts to react with molten iron 2 and slag 4. Further, for the purpose of reducing the production cost of molten iron 2 and reducing greenhouse gases, scrap as an iron source may be added into the furnace body 11 together with molten iron 2. Therefore, by incorporating auxiliary raw materials and scrap into the calculation model as a solid phase and considering the melting of the solid phase and the chemical reaction after melting, it becomes possible to perform the calculation more suitable for the actual operation.

さらに、上記実施形態では、処理結果として、例えば、脱炭酸素効率や脱炭速度、処理時間、スプラッシュの発生量等の、精錬処理において評価される慣用的な各種の指標を用いるとしたが、本発明はかかる例に限定されない。処理結果の上述の指標は、操業が行われる環境の違いから、重要度が変わることがある。例えば、生産量が求められるような環境下では、脱炭速度や脱炭速度、処理時間といった生産量に大きく寄与する指標が重要となる。一方、生産量がそれほど求められず生産能力に余裕があるような環境下では、脱炭酸素効率やスプラッシュの発生量といった、各種のガスや副原料の使用量の低減、歩留り向上に大きく寄与する指標が重要となる。このため、これらの指標をまとめた処理結果として生産コストを用い、この生産コストが最も低くなる計算条件を処理結果に適合するものとしてもよい。生産コストは、溶鉄2の処理に掛かるコストであり、求められる環境に応じて処理結果の複数の指標を金額化し、それらを合計することで算出することができる。例えば、生産量に寄与する指標の場合、生産量の増減に応じてコストの変化を計算することができる、また副原料等の使用量や歩留りに寄与する指標の場合、副原料やガス、製品となる鉄鋼の単価を用いることでコストを計算することができる。 Further, in the above embodiment, as the treatment result, various conventional indexes evaluated in the refining treatment, such as decarboxylation efficiency, decarburization rate, treatment time, and amount of splash generated, are used. The present invention is not limited to such examples. The above-mentioned indicators of the processing results may change in importance due to the difference in the operating environment. For example, in an environment where production volume is required, indicators such as decarburization rate, decarburization rate, and processing time that greatly contribute to production volume are important. On the other hand, in an environment where production volume is not required so much and there is a margin in production capacity, it greatly contributes to reduction of usage of various gases and auxiliary materials such as decarboxylation efficiency and splash generation, and improvement of yield. Indicators are important. Therefore, the production cost may be used as the processing result of summarizing these indexes, and the calculation condition at which the production cost is the lowest may be suitable for the processing result. The production cost is the cost required for the processing of the molten iron 2, and can be calculated by monetizing a plurality of indexes of the processing result according to the required environment and totaling them. For example, in the case of an index that contributes to production volume, the change in cost can be calculated according to the increase or decrease in production volume, and in the case of an index that contributes to the usage amount and yield of auxiliary raw materials, etc., auxiliary raw materials, gases, and products. The cost can be calculated by using the unit price of steel.

<実施形態の効果>
(1)本発明の一態様に係る精錬処理条件の決定方法は、溶鉄2に精錬ガス3を噴射して精錬処理を行う時の精錬処理条件を決定する方法であって、あらかじめ設定された精錬処理の初期条件及び終了条件をもとに精錬設備(例えば、転炉1)の内部(炉体11の内部)の経時的な現象を数値解析で推定する解析工程と、数値解析の結果に基づいて、溶鉄2の精錬処理条件を決定する決定工程と、を備える。
<Effect of embodiment>
(1) The method for determining the refining treatment conditions according to one aspect of the present invention is a method for determining the refining treatment conditions when the refining gas 3 is injected into the molten iron 2 to perform the refining treatment, and is a preset refining treatment condition. Based on the analysis process that estimates the temporal phenomenon inside the refining facility (for example, converter 1) (inside the furnace body 11) by numerical analysis based on the initial and end conditions of the process, and the result of the numerical analysis. A determination step for determining the refining treatment conditions for the molten iron 2 is provided.

上記(1)の構成によれば、精錬処理をする前に、数値解析を用いて内部の現象を模擬することにより、精錬処理時における精錬装置の内部の状態を精度よく推定することができる。これにより、スタティック制御あるいはダイナミック制御を用いた方法に比べ、溶鉄2の状態に応じて、効率よく精錬処理を行うことができる、精錬処理条件を提示することができる。また、スタティック制御では、精錬処理条件の決定をする際に、過去の操業実績を用いる必要があった。これに対して、上記(1)の構成によれば、精錬処理条件の決定に際して、過去の操業実績を用いる必要がないため、新規の鋼種といった過去には例がない精錬処理条件においても効率よく精錬処理を行うことができる。 According to the configuration of the above (1), the internal state of the refining apparatus at the time of the refining process can be accurately estimated by simulating the internal phenomenon by using numerical analysis before the refining process. As a result, as compared with the method using static control or dynamic control, it is possible to present refining processing conditions capable of efficiently performing refining processing according to the state of molten iron 2. In static control, it was necessary to use past operation results when determining refining processing conditions. On the other hand, according to the configuration of (1) above, it is not necessary to use the past operation results when determining the refining treatment conditions, so that the refining treatment conditions such as new steel grades, which have never been seen in the past, are efficiently used. Refining processing can be performed.

さらに、従来の方法では、スプラッシュの発生量や溶鉄2の成分濃度の経時的な変化は、実際の精錬処理では、直接的な測定が難しく、精度よく評価することが困難であった。しかし、上記(1)の構成によれば、精錬装置の内部の状態を模擬して推定、つまり上記実施形態のように界面の溶鉄の挙動や化学反応などを数値解析によって計算するため、スプラッシュの発生量や溶鉄2の成分濃度の経時的な変化を推定することができる。このため、スプラッシュの発生量の低減や、脱炭効率等の反応効率を上げること等を目的とした、最適な精錬処理条件を提示することができるようになる。 Further, in the conventional method, it is difficult to directly measure the change in the amount of splash generated and the component concentration of molten iron 2 with time in the actual refining treatment, and it is difficult to evaluate it accurately. However, according to the configuration of (1) above, the internal state of the refining apparatus is simulated and estimated, that is, the behavior of molten iron at the interface, the chemical reaction, etc. are calculated by numerical analysis as in the above embodiment, so that the splash It is possible to estimate the amount of generation and the change in the component concentration of molten iron 2 with time. Therefore, it becomes possible to present the optimum refining treatment conditions for the purpose of reducing the amount of splash generated and increasing the reaction efficiency such as decarburization efficiency.

(2)上記(1)の構成において、解析工程では、複数の操業条件に基づいて設定される複数の計算条件で数値解析を行い、決定工程では、複数の計算条件のうち、数値解析により得られる計算結果が終了条件に適合する計算条件を選択し、適合した計算条件に該当する操業条件を、精錬処理条件として決定する。
上記(2)の構成によれば、予め設定される終了条件に適合する精錬処理条件を、容易に決定することができる。
(3)上記(1)または(2)の構成において、解析工程では、少なくとも、溶鉄の自由界面の経時的な変化、スラグの自由界面の経時的な変化、溶鉄と精錬ガスとの化学反応、溶鉄内の化学反応、及び溶鉄とスラグとの化学反応、を推定する。
上記(3)の構成によれば、溶鉄2の自由界面で発生する反応量を、溶鉄2の形状に応じて精度よく推定することができるため、精錬処理をより効率よく行うことができる。
(2) In the configuration of (1) above, in the analysis process, numerical analysis is performed under a plurality of calculation conditions set based on a plurality of operating conditions, and in the determination process, a numerical analysis is performed among a plurality of calculation conditions. The calculation condition for which the calculated calculation result matches the end condition is selected, and the operating condition corresponding to the conforming calculation condition is determined as the refining processing condition.
According to the configuration of (2) above, the refining processing conditions that meet the preset end conditions can be easily determined.
(3) In the configuration of (1) or (2) above, in the analysis step, at least the change over time in the free interface of molten iron, the change over time in the free interface of slag, the chemical reaction between molten iron and refining gas, Estimate the chemical reaction in the molten iron and the chemical reaction between the molten iron and slag.
According to the configuration of (3) above, the amount of reaction generated at the free interface of molten iron 2 can be estimated accurately according to the shape of molten iron 2, so that the refining process can be performed more efficiently.

(4)本発明の一態様に係る精錬設備の制御方法は、上記(1)〜(3)のいずれかの精錬処理条件の決定方法により精錬処理条件を決定した後、精錬設備を制御し、精錬処理条件に従って溶鉄2を精錬処理する。
(5)本発明の一態様に係る溶鉄2の精錬処理方法は、溶鉄2に精錬ガス3を噴射して精錬処理する精錬設備にて溶鉄2を精錬処理する際に、上記(1)〜(3)のいずれかの精錬処理条件の決定方法により決定された精錬処理条件に従って、溶鉄2を精錬処理する。
上記(4),(5)の構成によれば、上記(1)と同様な効果を得ることができる。
(4) The method for controlling the smelting equipment according to one aspect of the present invention is to control the smelting equipment after determining the smelting treatment conditions by the method for determining the smelting treatment conditions according to any one of (1) to (3) above. The molten iron 2 is refined according to the refining conditions.
(5) The refining treatment method for molten iron 2 according to one aspect of the present invention is the above-mentioned (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) to (1) The molten iron 2 is refined according to the refining treatment conditions determined by the method for determining the refining treatment conditions according to any one of 3).
According to the configurations of (4) and (5) above, the same effect as that of (1) above can be obtained.

1 転炉
11 炉体
12 上吹きランス
13 底吹きノズル
2 溶鉄
3 精錬ガス
4 スラグ
5 撹拌ガス
1 converter 11 furnace body 12 top blown lance 13 bottom blown nozzle 2 molten iron 3 refining gas 4 slag 5 agitated gas

Claims (4)

溶鉄に精錬ガスを噴射して精錬処理を行う時の精錬処理条件を決定する方法であって、
あらかじめ設定された精錬処理の初期条件及び終了条件をもとに精錬設備の内部の経時
的な現象を数値解析で推定する解析工程と、
前記数値解析の結果に基づいて、前記溶鉄の精錬処理条件を決定する決定工程と、
を備え
前記解析工程では、
前記精錬設備の形状を模擬し、数値解析手法として格子法又は粒子法を用いた数値解析モデルを用い、
少なくとも、前記溶鉄の自由界面の経時的な変化、スラグの自由界面の経時的な変化、前記溶鉄と前記精錬ガスとの化学反応、前記溶鉄内の化学反応、及び前記溶鉄と前記スラグとの化学反応、を推定し、
前記精錬設備内部での少なくとも各種ガスや前記溶鉄、前記スラグの流体の流れを、各種化学反応と連成させて解くことで、前記精錬設備内部の各箇所における前記溶鉄の成分変化、前記スラグの発生状況、反応によるガスの発生状況及び温度変化の少なくとも一つを前記現象として推定することを特徴とする精錬処理条件の決定方法。
It is a method of determining the refining processing conditions when refining processing is performed by injecting refining gas into molten iron.
An analysis process that estimates the phenomenon over time inside the refining facility by numerical analysis based on the initial and end conditions of the refining process that have been set in advance.
A determination step for determining the refining treatment conditions for the molten iron based on the results of the numerical analysis, and
Equipped with a,
In the analysis step,
By simulating the shape of the refining equipment and using a numerical analysis model using the lattice method or particle method as the numerical analysis method,
At least, the change over time in the free interface of the molten iron, the change over time in the free interface of the slag, the chemical reaction between the molten iron and the refining gas, the chemical reaction in the molten iron, and the chemistry between the molten iron and the slag. Estimate the reaction,
By uncoupling the flow of at least various gases, the molten iron, and the fluid of the slag inside the refining facility with various chemical reactions to solve the changes in the components of the molten iron at each location inside the refining facility, the slag occurrence method of determining the refining process conditions that estimated to said Rukoto at least one occurrence and temperature changes of the gas by the reaction as the phenomenon.
前記解析工程では、複数の操業条件に基づいて設定される複数の計算条件で前記数値解析を行い、
前記決定工程では、複数の前記計算条件のうち、前記数値解析により得られる計算結果が前記終了条件に適合する前記計算条件を選択し、適合した前記計算条件に該当する前記操業条件を、前記精錬処理条件として決定することを特徴とする請求項1に記載の精錬処理条件の決定方法。
In the analysis step, the numerical analysis is performed under a plurality of calculation conditions set based on a plurality of operating conditions.
In the determination step, the calculation condition in which the calculation result obtained by the numerical analysis matches the end condition is selected from the plurality of calculation conditions, and the operating condition corresponding to the conforming calculation condition is refined. The method for determining a refining processing condition according to claim 1, wherein the refining processing condition is determined as a processing condition.
請求項1又は2のいずれか1項に記載の精錬処理条件の決定方法により前記精錬処理条件を決定した後、前記精錬設備を制御し、前記精錬処理条件に従って前記溶鉄を精錬処理することを特徴とする精錬設備の制御方法。 After determining the refining treatment conditions by the method for determining the refining treatment conditions according to any one of claims 1 or 2, the refining equipment is controlled to refine the molten iron according to the refining treatment conditions. How to control the refining equipment. 溶鉄に精錬ガスを噴射して精錬処理を行う精錬設備で前記溶鉄を精錬処理する際に、
請求項1又は2に記載の精錬処理条件の決定方法により決定された精錬処理条件に従って、前記溶鉄を精錬処理することを特徴とする溶鉄の精錬処理方法。
When refining the molten iron in a refining facility that injects refining gas into the molten iron to perform the refining process.
A method for refining molten iron, which comprises refining the molten iron according to the refining treatment conditions determined by the method for determining the refining treatment conditions according to claim 1 or 2 .
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